Optical tweezers: the next generation

Dholakia, Kishan; Spalding, Gabriel C.; MacDonald, Michael P.

doi:10.1088/2058-7058/15/10/37

Cited by 139 publications

(85 citation statements)

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“…The aim of this study was to test the hypothesis that intercellular RBC adhesion can occur directly (without participation of platelets). To perform this at the level of individual cells, we used the complementary methods of non-invasive holographic optical tweezers (HOT) [15], using the momentum of light and single-cell force spectroscopy to quantify the occurring adhesion.…”

Section: Introductionmentioning

confidence: 99%

Stimulation of human red blood cells leads to Ca2+-mediated intercellular adhesion

et al. 2011

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Red blood cells (RBCs) are a major component of blood clots, which form physiologically as a response to injury or pathologically in thrombosis. The active participation of RBCs in thrombus solidification has been previously proposed but not yet experimentally proven. Holographic optical tweezers and single-cell force spectroscopy were used to study potential cell-cell adhesion between RBCs. Irreversible intercellular adhesion of RBCs could be induced by stimulation with lysophosphatidic acid (LPA), a compound known to be released by activated platelets. We identified Ca 2+ as an essential player in the signaling cascade by directly inducing Ca 2+ influx using A23187. Elevation of the internal Ca 2+ concentration leads to an intercellular adhesion of RBCs similar to that induced by LPA stimulation. Using single-cell force spectroscopy, the adhesion of the RBCs was identified to be approximately 100 pN, a value large enough to be of significance inside a blood clot or in pathological situations like the vasco-occlusive crisis in sickle cell disease patients.

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Section: Introductionmentioning

confidence: 99%

Stimulation of human red blood cells leads to Ca2+-mediated intercellular adhesion

et al. 2011

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“…Since then, optical vortices have been intensively studied leading to many diverse applications (Allen et al, 2003(Allen et al, , 1999Andrews and Babiker, 2012), including optical tweezers and spanners for various applications (Dholakia et al, 2002;Grier, 2003;He et al, 1995;Ladavac and Grier, 2004): micromanipulation (Galajda and Ormos, 2001); classical and quantum communications (Yao and Padgett, 2011); phase contrast imaging in microscopy (Baranek and Bouchal, 2013;Fürhapter et al, 2005;Züchner et al, 2011); as well as further proposed applications in quantum information and metrology (Molina-Terriza et al, 2007;Yao and Padgett, 2011) and astronomy (Lee et al, 2006;Tamburini et al, 2011;Thidé et al, 2007). The discussion of photonic spin and orbital angular momentum in various situations, and the similarities and di↵erences between the two types of angular momentum have led to new ways of thinking about, and examining orbital angular momentum in this context.…”

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Electron vortices: Beams with orbital angular momentum

et al. 2017

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The recent prediction and subsequent creation of electron vortex beams in a number of laboratories occurred after almost 20 years had elapsed since the recognition of the physical significance and potential for applications of the orbital angular momentum carried by optical vortex beams. A rapid growth in interest in electron vortex beams followed, with swift theoretical and experimental developments. Much of the rapid progress can be attributed in part to the clear similarities between electron optics and photonics arising from the functional equivalence between the Helmholtz equations governing the free space propagation of optical beams and the time-independent Schrödinger equation governing freely propagating electron vortex beams. There are, however, key di↵erences in the properties of the two kinds of vortex beams. This review is concerned primarily with the electron type, with specific emphasis on the distinguishing vortex features: notably the spin, electric charge, current and magnetic moment, the spatial distribution as well as the associated electric and magnetic fields. The physical consequences and potential applications of such properties are pointed out and analysed, including nanoparticle manipulation and the mechanisms of orbital angular momentum transfer in the electron vortex interaction with matter.

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“…Forces due to applied light fields were first demonstrated experimentally by Lebedev [11], and the recoil of an absorbed photon on an atom was observed by Frisch who deflected an atomic beam with incoherent light [12]. With the advent of the laser, such forces have found many important applications, from decelerating, cooling and trapping atoms to optical tweezers in biology [13].Mirror-induced forces on individual atoms were first considered in connection with cavity-QED experiments, where their use has been proposed for trapping atoms in an optical resonator [14,15]. It is this kind of binding force which we observe in the experiment reported here.…”

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Forces between a Single Atom and Its Distant Mirror Image

Bushev¹,

Wilson²,

Eschner³

et al. 2004

Phys. Rev. Lett.

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An excited-state atom whose emitted light is back-reflected by a distant mirror can experience trapping forces, because the presence of the mirror modifies both the electromagnetic vacuum field and the atom's own radiation reaction field. We demonstrate this mechanical action using a single trapped barium ion. We observe the trapping conditions to be notably altered when the distant mirror is shifted by an optical wavelength. The well-localised barium ion enables the spatial dependence of the forces to be measured explicitly. The experiment has implications for quantum information processing and may be regarded as the most elementary optical tweezers.PACS numbers: 42.50. Pq, 42.50.Vk, 32.80.Pj, 42.50.Ct An atom which sits in the vicinity of mirrors or reflectors experiences energy shifts of its electronic states. These level shifts are known as the van der Waals, Casimir-Polder [1] and resonant radiative shifts [2,3], the latter of which is caused by a retarded interaction of the atom with its own radiation field. For an atom in its excited state and at distances from a mirror much less than the transition wavelength, the level shift will be dominated by the van der Waals interaction, whilst in the far field the level shift is attributed to the resonant interaction with its own reflected field [3,4,5,6]. Such far-field shifts have been observed with an atomic beam traversing an optical resonator [7] and with atoms in a microwave cavity [8]. The same effect has been predicted for a single trapped ion whose emitted radiation field is reflected back by a single, distant mirror [9], and recently this level shift has been observed with an indirect spectroscopic method [10].The far-field mirror-induced shift of an excited atomic level oscillates on the wavelength scale when the atommirror distance is varied. Therefore, when the position of the atom is controlled to the extent that it becomes sensitive to this spatial dependence, then the level shift acts as a spatially varying potential U ( r), and the atom feels its gradient − ∇U ( r) as a force.This mirror-induced force is a peculiar manifestation of the mechanical effects of light. Forces due to applied light fields were first demonstrated experimentally by Lebedev [11], and the recoil of an absorbed photon on an atom was observed by Frisch who deflected an atomic beam with incoherent light [12]. With the advent of the laser, such forces have found many important applications, from decelerating, cooling and trapping atoms to optical tweezers in biology [13].Mirror-induced forces on individual atoms were first considered in connection with cavity-QED experiments, where their use has been proposed for trapping atoms in an optical resonator [14,15]. It is this kind of binding force which we observe in the experiment reported here. A single, trapped and laser-excited ion is an ideal system for this observation, as its position can be controlled on the nanometer scale [16,17,18], and interaction with a distant mirror has already been demonstrated [10,16,19]. These e...

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Optical tweezers: the next generation

Cited by 139 publications

References 0 publications

Stimulation of human red blood cells leads to Ca2+-mediated intercellular adhesion

Stimulation of human red blood cells leads to Ca2+-mediated intercellular adhesion

Electron vortices: Beams with orbital angular momentum

Forces between a Single Atom and Its Distant Mirror Image

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